You've just reminded me that I bought the book years ago but have never read it! It must be lying around the house somewhere, unless it was accidentally disposed of in one of my Great Recycling Purges ...I read the book the film was based on called "Do Androids Dream of Electric Sheep" by Phillip K Dick a long time ago.
I think that some films should not have sequels.
Incidentally, the footage shown at the end of the movie was not in the original cut. It's stock footage from Kubrick's The Shining.
I think the idea of films 'set in the same Universe as' other sucessful films is a good idea. It doesn't detract from the original and doesn't spoil it if it is rubbish. It also allows known characters to be mentioned but without needing to bring back an aging actor to play younger versions of themselves.well there was this: http://www.guardian.co.uk/film/2012/feb/06/harrison-ford-blade-runner-sequel followed by this: http://www.guardian.co.uk/film/2012/feb/07/harrison-ford-blade-runner-sequel?intcmp=239
Shame
Quite a few well known movies are based on Phillip K Dick stories